How can my comcast.net users get email from jotform?

None of my users who have Comcast email can get a copy of their submission.

Comcast happens to be one of the email services having very strict policies to emails to as much as usually common usage of automated emails are being rejected by them. If by using noreply email of Jotform as your sender does not reach Comcast, I suggest to try setting up your own email as your email sender via SMTP. 

You can check this guide to know how to setup SMTP on your account: https://www.jotform.com/help/244-How-to-Setup-SMTP-for-a-Form

You may also review your email activity history to check the delivery status of your email alerts: https://www.jotform.com/help/293-How-to-View-All-Your-Form-Email-History

If you have other questions, please let us know.